Spring动态数据源实现读写分离详解

package com.bounter.mybatis.extension;/** * 基于ThreadLocal实现的动态数据源容器，保证DynamicDataSource的线程安全性 * @author simon * */public class DynamicDataSourceHolder { private static final ThreadLocal<String> dataSourceHolder = new ThreadLocal<>(); public static void setDataSource(String dataSourceKey) { dataSourceHolder.set(dataSourceKey); } public static String getDataSource() { return dataSourceHolder.get(); } public static void clearDataSource() { dataSourceHolder.remove(); }}

package com.bounter.mybatis.extension;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;/** * 自定义的Spring 动态数据源扩展类,用来实现Master、Slave数据源动态切换 * @author simon * */public class DynamicDataSource extends AbstractRoutingDataSource { @Override protected Object determineCurrentLookupKey() { //使用DynamicDataSourceHolder保证线程安全 return DynamicDataSourceHolder.getDataSource(); }}

# Master DBdb.master.url=jdbc:mysql://192.168.168.110:3306/bounter?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true&serverTimezone=PRC&useSSL=falsedb.master.username=bounter# AES encrypt,Base64 encodedb.master.password=ZNhnEjauk3pecZxxS84ofA==# Slave DBdb.slave.url=jdbc:mysql://192.168.168.111:3306/database?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true&serverTimezone=PRC&useSSL=falsedb.slave.username=bounter# AES encrypt,Base64 encodedb.slave.password=jFYmt2f57RHhzItYDhWiSA==

<!-- Master数据源 --><bean id="masterDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> <!-- 基本属性 url、user、password --> <property name="url" value="${db.master.url}" /> <property name="username" value="${db.master.username}" /> <property name="password" value="${db.master.password}" /> <!-- 配置初始化大小、最小、最大 --> <property name="initialSize" value="20" /> <property name="minIdle" value="1" /> <property name="maxActive" value="40" /> <!-- 配置获取连接等待超时的时间 --> <property name="maxWait" value="60000" /> <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 --> <property name="timeBetweenEvictionRunsMillis" value="60000" /> <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 --> <property name="minEvictableIdleTimeMillis" value="300000" /> <property name="validationQuery" value="SELECT 'x'" /> <property name="testWhileIdle" value="true" /> <property name="testOnBorrow" value="false" /> <property name="testOnReturn" value="false" /> <!-- 配置监控统计拦截的filters --> <property name="filters" value="stat" /></bean><!-- Slave数据源 --><bean id="slaveDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> <!-- 基本属性 url、user、password --> <property name="url" value="${db.slave.url}" /> <property name="username" value="${db.slave.username}" /> <property name="password" value="${db.slave.password}" /> <!-- 配置初始化大小、最小、最大 --> <property name="initialSize" value="20" /> <property name="minIdle" value="1" /> <property name="maxActive" value="40" /> <!-- 配置获取连接等待超时的时间 --> <property name="maxWait" value="60000" /> <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 --> <property name="timeBetweenEvictionRunsMillis" value="60000" /> <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 --> <property name="minEvictableIdleTimeMillis" value="300000" /> <property name="validationQuery" value="SELECT 'x'" /> <property name="testWhileIdle" value="true" /> <property name="testOnBorrow" value="false" /> <property name="testOnReturn" value="false" /> <!-- 配置监控统计拦截的filters --> <property name="filters" value="stat" /></bean><!-- 自定义动态数据源 --> <bean id="dataSource" class="com.bounter.mybatis.extension.DynamicDataSource"> <property name="targetDataSources">  <map key-type="java.lang.String">  <!-- 配置读写数据源 -->  <entry value-ref="masterDataSource" key="write"></entry>  <entry value-ref="slaveDataSource" key="read"></entry>  </map> </property> <property name="defaultTargetDataSource" ref="masterDataSource"></property> </bean>

package com.bounter.mybatis.aop;import org.aspectj.lang.JoinPoint;import org.aspectj.lang.annotation.After;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Before;import org.springframework.context.annotation.EnableAspectJAutoProxy;import org.springframework.stereotype.Component;import com.bounter.mybatis.extension.DynamicDataSourceHolder;/** * 数据源切面，通过dao方法前缀决定访问读、写数据源 * @author simon * */@Component@Aspect@EnableAspectJAutoProxy(proxyTargetClass = true)public class DataSourceAspect { //读库数据源key private static final String DATASOURCE_KEY_READ = "read"; //查询方法清单 String[] queryMethods = {"find","get","query","count","select"}; /** * dao层方法执行前选择数据源 * @param point */ @Before("execution(* com.bounter.mybatis.dao..*.*(..))") public void before(JoinPoint point) { // 获取到当前执行的方法名 String methodName = point.getSignature().getName(); //匹配查询方法 for(String queryMethod : queryMethods) {  if(methodName.startsWith(queryMethod)) {  //查询方法设置数据源为读库  DynamicDataSourceHolder.setDataSource(DATASOURCE_KEY_READ);  break;  } } } /** * dao层方法执行完后清空数据源选择 * @param point */ @After("execution(* com.bounter.mybatis.dao..*.*(..))") public void after(JoinPoint point) { DynamicDataSourceHolder.clearDataSource(); }}